Impinging stream drying

In the previous chapters the essential principles and characteristics of gas-continuous impinging streams (GIS) were discussed while this and subsequent chapters in Part I will focus on the research and development of applied technologies. The contents have been chosen to be as valuable as possible for practical application, while successful or unsuccessful experiences included can be used for reference. 

As mentioned, like any other technical method, the method of impinging streams (IS) cannot be a universal tool. On one hand, IS has the outstanding advantage of significantly enhancing heat and mass transfer between phases while on the other, it also has its intrinsic faults. From the discussions in the previous chapters, the essential characteristics of gas-continuous impinging streams can be summarized briefly as follows  

On the other hand, the industrial application of a new technological method must face many practical engineering problems, in addition to those of the method itself, which must be solved appropriately with the ideas of system engineering. Otherwise, successful application is difficult, even if the technology is very nice. 

Assimilating positive and negative the experiences obtained in the past, the author of this book has developed the Circulative Impinging Stream Dryer , an IS device suitable for powdery and/or granular materials [11, 82]. A test with quasi-industrial equipment on a scale of 1000 tones per year has exhibited good performance, and practical application may be expected in the near future. 

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Figure 6.1 Impinging stream drying system for aluminum sulfate [86, 87].

Wu Yuan, Cheng, Rong and Sun, Qin (1996). Internal circulative impinging stream drying (I) An experimental study under cold condition. Proc. of 96 Chinese Forum on Drying, Beijing, 112-120 (in Chinese). 

Although no details are available, an impinging stream dryer for sludges using super-heated steam as the drying medium has been operated at pilot scale successfully in Russia. Mujumdar has presented additional information on these special types of dryers [1] (see chapter on impinging stream drying in this handbook). 

Choicharoen, K. Devahastin, S. Soponronnarit, S. Numerical simulation of multiphase transport phenomena during impinging stream drying of a particulate material. Drying Technology 2012, 30, 1227-1237. 

Swasdisevi, T. Devahastin, S. Thanasookprasert, S. Soponronnarit, S. Comparative evaluation of hot-air and superheated-steam impinging stream drying as novel alternatives for paddy drying. Drying Technology 2013, 31(6), 715-725. 

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